Q.850 to SIP Code Table

The following table describes the mappings implemented by FreeSwitch (see mod_sofia.c:hangup_cause_to_sip). Unspecified causes codes (no value in the "SIP Equiv." column in the table) are translated to SIP "480 Temporarily Unavailable" by FreeSwitch.

The table also contains non-standard codes above 127 (ISUP and ISDN only specify codes up to 127). These codes are used internally to FreeSwitch to indicate other states. (These codes do not map directly to SIP error codes either.) The complete list of SWITCH_CAUSE_ codes (switch_call_cause_t) is defined in include/switch_types.h.

See ITU-T Q.850 standard for a formal definition of standard telephony disconnect cause codes for ISDN, and the mapping between Q.931 (DSSS1) and ISUP codes.

See ITU Q.1912.5 for a formal definition of interoperability between ISUP and SIP, especially section 6.11 which specifies the "Reason" header and gives the mapping of the disconnect cause codes between ISUP and SIP.

Another set of mappings are the Q.SIG / SIP mappings from RFC 4497 section 8.4.1. (Q.SIG is one of many extensions to Q.931 used for PBX-to-PBX signalling on private links.)

This is usually given by the router when none of the other codes apply. This cause usually occurs in the same type of situations as cause 1, cause 88, and cause 100.

1

404

UNALLOCATED_NUMBER

Unallocated (unassigned) number [Q.850 value 1]

This cause indicates that the called party cannot be reached because, although the called party number is in a valid format, it is not currently allocated (assigned).

2

404

NO_ROUTE_TRANSIT_NET

No route to specified transit network (national use) [Q.850]

This cause indicates that the equipment sending this cause has received a request to route the call through a particular transit network, which it does not recognize. The equipment sending this cause does not recognize the transit network either because the transit network does not exist or because that particular transit network, while it does exist, does not serve the equipment which is sending this cause.

3

404

NO_ROUTE_DESTINATION

No route to destination [Q.850]

This cause indicates that the called party cannot be reached because the network through which the call has been routed does not serve the destination desired. This cause is supported on a network dependent basis.

6

CHANNEL_UNACCEPTABLE

channel unacceptable [Q.850]

This cause indicates that the channel most recently identified is not acceptable to the sending entity for use in this call.

7

CALL_AWARDED_DELIVERED

call awarded, being delivered in an established channel [Q.850]

This cause indicates that the user has been awarded the incoming call, and that the incoming call is being connected to a channel already established to that user for similar calls (e.g. packet-mode x.25 virtual calls).

16

NORMAL_CLEARING

normal call clearing [Q.850]

This cause indicates that the call is being cleared because one of the users involved in the call has requested that the call be cleared. Under normal situations, the source of this cause is not the network.

17

486

USER_BUSY

user busy [Q.850]

This cause is used to indicate that the called party is unable to accept another call because the user busy condition has been encountered. This cause value may be generated by the called user or by the network. In the case of user determined user busy it is noted that the user equipment is compatible with the call.

18

408

NO_USER_RESPONSE

no user responding [Q.850]

This cause is used when a called party does not respond to a call establishment message with either an alerting or connect indication within the prescribed period of time allocated.

19

480

NO_ANSWER

no answer from user (user alerted) [Q.850]

This cause is used when the called party has been alerted but does not respond with a connect indication within a prescribed period of time. Note - This cause is not necessarily generated by Q.931 procedures but may be generated by internal network timers.

20

480

SUBSCRIBER_ABSENT

subscriber absent [Q.850]

This cause value is used when a mobile station has logged off, radio contact is not obtained with a mobile station or if a personal telecommunication user is temporarily not addressable at any user-network interface. Sofia SIP will normally raise USER_NOT_REGISTERED in such situations.

21

603

CALL_REJECTED

call rejected [Q.850]

This cause indicates that the equipment sending this cause does not wish to accept this call, although it could have accepted the call because the equipment sending this cause is neither busy nor incompatible. The network may also generate this cause, indicating that the call was cleared due to a supplementary service constraint. The diagnostic field may contain additional information about the supplementary service and reason for rejection.

22

410

NUMBER_CHANGED

number changed [Q.850]

This cause is returned to a calling party when the called party number indicated by the calling party is no longer assigned, The new called party number may optionally be included in the diagnostic field. If a network does not support this cause, cause no: 1, unallocated (unassigned) number shall be used.

23

410

REDIRECTION_TO_NEW_DESTINATION

This cause is used by a general ISUP protocol mechanism that can be invoked by an exchange that decides that the call should be set-up to a different called number. Such an exchange can invoke a redirection mechanism, by use of this cause value, to request a preceding exchange involved in the call to route the call to the new number.

25

483

EXCHANGE_ROUTING_ERROR

This cause indicates that the destination indicated by the user cannot be reached, because an intermediate exchange has released the call due to reaching a limit in executing the hop counter procedure. This cause is generated by an intermediate node, which when decrementing the hop counter value, gives the result 0.

27

502

DESTINATION_OUT_OF_ORDER

destination out of order [Q.850]

This cause indicates that the destination indicated by the user cannot be reached because the interface to the destination is not functioning correctly. The term "not functioning correctly" indicates that a signal message was unable to be delivered to the remote party; e.g. a physical layer or data link layer failure at the remote party, or user equipment off-line.

28

484

INVALID_NUMBER_FORMAT

invalid number format (address incomplete) [Q.850]

This cause indicates that the called party cannot be reached because the called party number is not in a valid format or is not complete.

29

501

FACILITY_REJECTED

facilities rejected [Q.850]

This cause is returned when a supplementary service requested by the user cannot be provide by the network.

30

RESPONSE_TO_STATUS_ENQUIRY

response to STATUS INQUIRY [Q.850]

This cause is included in the STATUS message when the reason for generating the STATUS message was the prior receipt of a STATUS INQUIRY.

31

480

NORMAL_UNSPECIFIED

normal, unspecified [Q.850]

This cause is used to report a normal event only when no other cause in the normal class applies.

34

503

NORMAL_CIRCUIT_CONGESTION

no circuit/channel available [Q.850]

This cause indicates that there is no appropriate circuit/channel presently available to handle the call.

38

503

NETWORK_OUT_OF_ORDER

network out of order [Q.850]

This cause indicates that the network is not functioning correctly and that the condition is likely to last a relatively long period of time e.g. immediately re-attempting the call is not likely to be successful.

41

503

NORMAL_TEMPORARY_FAILURE

temporary failure [Q.850]

This cause indicates that the network is not functioning correctly and that the condition is not likely to last a long period of time; e.g. the user may wish to try another call attempt almost immediately.

42

503

SWITCH_CONGESTION

switching equipment congestion [Q.850]

This cause indicates that the switching equipment generating this cause is experiencing a period of high traffic.

43

ACCESS_INFO_DISCARDED

access information discarded [Q.850]

This cause indicates that the network could not deliver access information to the remote user as requested, i.e. user-to-user information, low layer compatibility, high layer compatibility or sub-address as indicated in the diagnostic. It is noted that the particular type of access information discarded is optionally included in the diagnostic.

44

503

REQUESTED_CHAN_UNAVAIL

requested circuit/channel not available [Q.850]

This cause is returned when the other side of the interface cannot provide the circuit or channel indicated by the requesting entity.

45

PRE_EMPTED

47

resource unavailable, unspecified [Q.850]

This cause is used to report a resource unavailable event only when no other cause in the resource unavailable class applies.

50

FACILITY_NOT_SUBSCRIBED

requested facility not subscribed [Q.850

This cause indicates that the user has requested a supplementary service, which is available, but the user is not authorized to use.

52

403

OUTGOING_CALL_BARRED

outgoing calls barred

This cause indicates that although the calling party is a member of the CUG for the outgoing CUG call, outgoing calls are not allowed for this member of the CUG.

54

403

INCOMING_CALL_BARRED

incoming calls barred

This cause indicates that although the called party is a member of the CUG for the incoming CUG call, incoming calls are not allowed to this member of the CUG.

57

403

BEARERCAPABILITY_NOTAUTH

bearer capability not authorized [Q.850]

This cause indicates that the user has requested a bearer capability that is implemented by the equipment which generated this cause but the user is not authorized to use.

58

503

BEARERCAPABILITY_NOTAVAIL

bearer capability not presently available [Q.850]

This cause indicates that the user has requested a bearer capability which is implemented by the equipment which generated this cause but which is not available at this time.

63

SERVICE_UNAVAILABLE

service or option not available, unspecified [Q.850]

This cause is used to report a service or option not available event only when no other cause in the service or option not available class applies.

65

488

BEARERCAPABILITY_NOTIMPL

bearer capability not implemented [Q.850]

This cause indicates that the equipment sending this cause does not support the bearer capability requested.

66

CHAN_NOT_IMPLEMENTED

channel type not implemented [Q.850]

This cause indicates that the equipment sending this cause does not support the channel type requested

69

501

FACILITY_NOT_IMPLEMENTED

requested facility not implemented [Q.850]

This cause indicates that the equipment sending this cause does not support the requested supplementary services.

79

501

SERVICE_NOT_IMPLEMENTED

service or option not implemented, unspecified [Q.850]

This cause is used to report a service or option not implemented event only when no other cause in the service or option not implemented class applies.

81

INVALID_CALL_REFERENCE

invalid call reference value [Q.850]

This cause indicates that the equipment sending this cause has received a message with a call reference which is not currently in use on the user-network interface.

88

488

INCOMPATIBLE_DESTINATION

incompatible destination [Q.850]

This cause indicates that the equipment sending this cause has received a request to establish a call which has low layer compatibility, high layer compatibility or other compatibility attributes (e.g. data rate) which cannot be accommodated.

95

INVALID_MSG_UNSPECIFIED

invalid message, unspecified [Q.850]

This cause is used to report an invalid message event only when no other cause in the invalid message class applies.

96

MANDATORY_IE_MISSING

mandatory information element is missing [Q.850]

This cause indicates that the equipment sending this cause has received a message which is missing an information element which must be present in the message before that message can be processed.

97

MESSAGE_TYPE_NONEXIST

message type non-existent or not implemented [Q.850]

This cause indicates that the equipment sending this cause has received a message with a message type it does not recognize either because this is a message not defined of defined but not implemented by the equipment sending this cause.

98

WRONG_MESSAGE

message not compatible with call state or message type non-existent or not implemented. [Q.850]

This cause indicates that the equipment sending this cause has received a message such that the procedures do not indicate that this is a permissible message to receive while in the call state, or a STATUS message was received indicating an incompatible call state.

This cause indicates that the equipment sending this cause has received a message which includes information element(s)/parameter(s) not recognized because the information element(s)/parameter name(s) are not defined or are defined but not implemented by the equipment sending the cause. This cause indicates that the information element(s)/parameter(s) were discarded. However, the information element is not required to be present in the message in order for the equipment sending the cause to process the message.

100

INVALID_IE_CONTENTS

Invalid information element contents [Q.850]

This cause indicates that the equipment sending this cause has received and information element which it has implemented; however, one or more fields in the I.E. are coded in such a way which has not been implemented by the equipment sending this cause.

101

WRONG_CALL_STATE

message not compatible with call state [Q.850]

This cause indicates that a message has been received which is incompatible with the call state.

102

504

RECOVERY_ON_TIMER_EXPIRE

recovery on timer expiry [Q.850]

This cause indicates that a procedure has been initiated by the expiration of a timer in association with error handling procedures. This is often associated with NAT problems. Ensure that "NAT Mapping Enable" is turned on in your ATA. If it is not NAT related it can sometimes be provider related, make sure to ensure another outbound provider does not solve the problem.

FreeSWITCH also returns this when the remote party sends a 408 for call expired.

This cause indicates that the equipment sending this cause has received a message which includes parameters not recognized because the parameters are not defined or are defined but not implemented by the equipment sending this cause. The cause indicates that the parameter(s) were ignored. In addition, if the equipment sending this cause is an intermediate point, then this cause indicates that the parameter(s) were passed unchanged.

111

PROTOCOL_ERROR

protocol error, unspecified [Q.850]

This cause is used to report a protocol error event only when no other cause in the protocol error class applies.

127

INTERWORKING

Interworking, unspecified [Q.850]

This cause indicates that an interworking call (usually a call to SW56 service) has ended.

487

487

ORIGINATOR_CANCEL

500

CRASH

501

SYSTEM_SHUTDOWN

502

LOSE_RACE

503

MANAGER_REQUEST

This cause is used when you send an api command to make it hangup. For example uuid_kill <uuid>

600

BLIND_TRANSFER

601

ATTENDED_TRANSFER

602

ALLOTTED_TIMEOUT

603

USER_CHALLENGE

604

MEDIA_TIMEOUT

605

PICKED_OFF

This cause means the call was picked up by intercepting it from another extension (i.e. dialing **ext_number from another extension).

606

USER_NOT_REGISTERED

This means you tried to originate a call to a SIP user who forgot to register.